Contents — Hogweed.org

Hogweed.org has 19 articles in its current edition, and a great many more waiting to be written.

Articles

Giant hogweed: Giant hogweeds are tall invasive plants of the genus Heracleum. A single plant sheds tens of thousands of seeds, its sap burns skin that is later exposed to light, and cutting off the top only encourages it to grow back.
Control of giant hogweed: Hogweed returns from its root and from a seed bank that outlives every plant. Control that lasts attacks the root, keeps going until the seed bank is exhausted, and covers every property in the catchment at once.
Phytophotodermatitis: A burn caused by plant sap that is harmless in the dark. Contact does not hurt; the injury appears a day or two later, once the skin has been exposed to light, and its marks can last for years.
Seed bank: The reserve of viable seeds stored in the soil. In giant hogweed it outlives every visible plant: remove the stand and the seed bank quietly replaces it, unless it is starved of new deposits for several years in a row.
Hydra effect: In population ecology, the paradox in which killing more individuals produces a larger population. Hogweed that is cut but not uprooted is a textbook case.
Umbel: The flower head of the carrot family, in which the flower stalks spring from one point like the ribs of an umbrella. On a giant hogweed the umbels form a hierarchy of four orders: the umbel at the top sets nearly half of the seed, and those at the bottom set almost none.
Heracleum: The genus of the hogweeds: sixty to a hundred and twenty species of the carrot family, most of them harmless. Three of the largest have become invaders, and botanists are still arguing about what to call them.
Enemy release hypothesis: The idea that invaders thrive because they left their enemies at home. Giant hogweed turned out to have no enemies of its own anywhere: those that eat it eat parsnips too. In the long run, its own soil turns against it.
Furanocoumarin: Plant compounds that are harmless in the dark and bind to DNA in ultraviolet light. They make hogweed sap burn, cleared psoriasis in the first photochemotherapy, cause the grapefruit–drug interaction, and have kept plants and caterpillars in an arms race for millions of years.
Sosnowsky’s hogweed: A giant hogweed of the Caucasus, planted across the Soviet Union from 1947 as a high-yielding silage crop. It burned the farm workers and tainted the milk, was abandoned in the 1980s, and spread without check when the fields were left in the 1990s.
Common hogweed: The native hogweed of European meadows and verges, type species of its genus and namesake of the giants. Its fermented leaves made the soup barszcz, served to Kraków professors in Lent and later eaten by the poor, until beetroot took its place and its name.
Persian hogweed: A perennial hogweed of Iran, where its fruit is the spice golpar, and of northern Norway, where it is the Tromsø palm: an emblem of the city, and a weed its biodiversity agency does not expect to be rid of within the current interglacial.
Lag phase: The decades an invader may spend doing apparently nothing before it explodes. Giant hogweed waited in European gardens for most of a century; then the landscape changed, and its range began to double every ten to fourteen years.
Parsnip webworm: A small moth whose caterpillars eat only the flowers and seed of parsnips and hogweeds, under webs they defend as territory. When it caught up with wild parsnip in North America, the plant grew more toxic; the holes it chews in hogweed stems house earwigs and woodlice long after it has gone.
Alternatives: What is recommended in place of giant hogweed: garden plants to grow instead of it, grass to sow on land cleared of it, and sheep to graze that land afterwards. The sources also give the costs; in Russia in 2024, one public contract in 475 paid for sowing grass.
The Return of the Giant Hogweed: A 1971 song by Genesis in which a Victorian explorer brings the giant hogweed to Kew, and the plant escapes, spreads and survives every attempt to destroy it. The scientific monograph on the plant quotes it at the head of its chapters.
Hogweed (disambiguation): Hogweed may refer to several tall plants of the carrot family, above all the invasive giant hogweeds, and to a few unrelated weeds that pigs were once thought fit to eat.
Hogquote: Weeds and roots: Quotations about weeds, roots and gardens, from Shakespeare’s gardener to the proverb that one year’s seeding makes seven years’ weeding. Held in common, like everything else here.
Glossary of hogweed terms: Botanical, chemical and ecological terms used in hogweed control, from apical dominance to stratification. Several words have acquired other meanings outside botany; this glossary uses only the botanical ones.

Wanted articles

Pages that are linked from existing articles but have not yet been written, by number of requests.

Business cycle (1,929 links)
Planned eradication (1,871 links)
Holding company (44 links)
Bank (12 links)
Seed vault (9 links)
Lernaean Hydra (2 links)
Class enemy (1 links)

Articles

Categories

Apiaceae

Articles with disputed neutrality

Biological pest control

Botanical terminology

Carcinogens

Chemical ecology

Codes of conduct

Coevolution

Coumarins

Debts

Depressariidae

Disambiguation pages

Ecological restoration

Ecosystem engineers

Flora of Europe

Flora of Iran

Fodder crops that did not justify the trust placed in them

Fodder plants

Former red links

Garden plants introduced in the 19th century

Genesis songs

Glossaries

Grazing

Hierarchies

Hogquote

Hogweed in popular culture

Horticulture

Hypotheses

Invasion biology

Invasive insect species

Invasive plant species in Europe

Invasive plant species in North America

Invasive species management

Medical emergencies of the countryside

Monocarpic plants

Moths of Europe

Pages semi-protected against stakeholder edits

Paradoxes

Pests of parsnip

Phototoxic plants

Phototoxicity

Plant common name disambiguation pages

Plant dermatitis

Plant genera

Plant morphology

Plant reproduction

Plant toxins

Plants named after pigs

Pollination

Population ecology

Quotations about plants

Reserves

Soil ecology

Songs about plants

Soups

Soviet agriculture

Spices

Symbols of Tromsø

Taxonomic controversies

Things that grow back

Type species

Volunteering

Weed control

Wanted articles